PHOENIX –Lockheed Martin, prime contractor for the National Oceanic and Atmospheric Administration’s Geostationary Operational Environmental Satellites (GOES) R Series, has halted work on GOES-T, the next spacecraft scheduled to launch, and turned its attention to successor GOES-U as it waits for Harris Corp. to complete modification of the spacecraft’s primary instrument, the Advanced Baseline Imager (ABI).

“It’s nice to have all the hardware for two vehicles,” Tim Gasparrini, GOES-R program manager for Lockheed Martin Space, told SpaceNews. “I can swap it out instead of waiting.”

Lockheed Martin had finished assembling the GOES-T spacecraft last year and was preparing for environmental testing when NOAA directed the company to halt work due to problems with ABI on the GOES-17 satellite launched in March 2018. During on-orbit checkout, NOAA discovered ABI’s infrared channels were not working as designed because of cooling problems.

Specifically, the loop heat pipes, built by ATK, now part of Northrop Grumman, for Exelis, now part of Harris Corp., to transfer heat to the radiator, were unable to adequately cool the imager’s infrared and near infrared channels for approximately 12 hours a day.

Many of those problems have been resolved. GOES-17’s ABI is expected to deliver about 97 percent of the data it was built to collect, according to Harris and Lockheed Martin officials attending the American Meteorological Society conference here. NOAA planned to share details at the conference of work to optimize ABI performance, fill remaining data gaps with other satellites and evaluate the impact of the ABI anomaly on customers. That presentation was cancelled due to the government shutdown.

Since Lockheed Martin pulled ABI off GOES-T and shipped it to Harris in October, Harris has been working with NOAA and Northrop Grumman to redesign the loop heat pipes. The modified version, which relies on ammonia coolant rather than propylene like GOES-17’s ABI, was slated for a critical design review in early January, said Paul Wloszek, Harris Space and Intelligence Systems environmental sensors director. That review has been delayed by the government shutdown.

Lockheed Martin, meanwhile, plans to make slight changes to the GOES-T spacecraft to accommodate the modified ABI. “We are adding some more sensors to monitor better and giving them a little more power,” Gasparinni said. “All that needs to be finalized in the critical design review.”

Now it is clear NOAA will not launch GOES-T in May 2020. “When we will launch exactly depends on when this all settles down,” Gasparrini said. “They don’t expect the 2024 launch of GOES-U to be impacted.”

While Harris works on ABI, Lockheed Martin is assembling GOES-U.

“We are trying to not let the spacecraft program get impacted by this,” Gasparrini said. “Once the ABI comes back, we’ll stop work on GOES-U, jump over to GOES-T, install the ABI and test it.”